X

Search Results

Searching....

7.10 Coupled-Cluster Excited-State and Open-Shell Methods

7.10.21 EOM-CC Optimization and Properties Job Control

(July 14, 2022)

CC_STATE_TO_OPT

CC_STATE_TO_OPT
       Specifies which state to optimize (or from which state compute EOM-EOM inter-state properties).
TYPE:
       INTEGER ARRAY
DEFAULT:
       None
OPTIONS:
       [i,j] optimize the jth state of the ith irrep.
RECOMMENDATION:
       None

Note:  The state number should be smaller or equal to the number of excited states calculated in the corresponding irrep.

Note:  If analytic gradients are not available, the finite difference calculations will be performed and the symmetry will be turned off. In this case, CC_STATE_TO_OPT should be specified assuming C1 symmetry, i.e., as [1,N] where N is the number of state to optimize (the states are numbered from 1).

CC_EOM_PROP

CC_EOM_PROP
       Whether or not the non-relaxed (expectation value) one-particle EOM-CCSD target state properties will be calculated. Available properties currently include permanent dipole moment, angular momentum projections, the second moments (x2, y2, and z2) of the electron density along with r2=x2+y2+z2. This option is incompatible with JOBTYPE = FORCE, OPT, or FREQ.
TYPE:
       LOGICAL
DEFAULT:
       FALSE (no one-particle properties will be calculated)
OPTIONS:
       FALSE, TRUE
RECOMMENDATION:
       Additional equations (EOM-CCSD equations for the left eigenvectors) need to be solved for properties, approximately doubling the cost of calculation for each irrep. The cost of the one-particle properties calculation itself is low. The one-particle density of an EOM-CCSD target state can be analyzed with NBO or libwfa packages by specifying the state with CC_STATE_TO_OPT and requesting NBO = TRUE and CC_EOM_PROP = TRUE.

CC_TRANS_PROP

CC_TRANS_PROP
       Whether or not the transition dipole moment (in atomic units) and oscillator strength and rotatory strength (in atomic units) for the EOM-CCSD target states will be calculated. By default, the transition dipole moment, angular momentum matrix elements, and rotatory strengths are calculated between the CCSD reference and the EOM-CCSD target states. In order to calculate transition dipole moment, angular momentum matrix elements, and rotatory strengths between a set of EOM-CCSD states and another EOM-CCSD state, the CC_STATE_TO_OPT must be specified for this state.
TYPE:
       INTEGER
DEFAULT:
       0 (no transition properties will be calculated)
OPTIONS:
       1 (calculate transition properties between all computed EOM state and the reference state) 2 (calculate transition properties between all pairs of EOM states)
RECOMMENDATION:
       Additional equations (for the left EOM-CCSD eigenvectors plus lambda CCSD equations in case of transition properties between the CCSD reference and EOM-CCSD target states are requested) need to be solved for transition properties, approximately doubling the computational cost. The cost of the transition properties calculation itself is low.

Note:  When the $trans_prop section is present in the input, it overrides the setting of the CC_TRANS_PROP $rem variable. However, for $trans_prop to work, CC_TRANS_PROP does need to be set.

CC_EOM_ECD

CC_EOM_ECD
       Whether or not the ECD transition moments will be calculated. By default, the transition moments are calculated between the CCSD reference and the EOM-CCSD target states. In order to calculate transition moments between a set of EOM-CCSD states and another EOM-CCSD state, the CC_STATE_TO_OPT must be specified for this state.
TYPE:
       LOGICAL
DEFAULT:
       FALSE (do not compute ECD transition moments)
OPTIONS:
       TRUE Compute ECD transition moments.
RECOMMENDATION:
       Activate for chiral molecules only.

CC_EOM_2PA

CC_EOM_2PA
       Whether or not the transition moments and cross-sections for two-photon absorption will be calculated. By default, the transition moments are calculated between the CCSD reference and the EOM-CCSD target states. In order to calculate transition moments between a set of EOM-CCSD states and another EOM-CCSD state, the CC_STATE_TO_OPT must be specified for this state. If 2PA NTO analysis is requested, the CC_EOM_2PA value is redundant as long as CC_EOM_2PA >0.
TYPE:
       INTEGER
DEFAULT:
       0 (do not compute 2PA transition moments)
OPTIONS:
       1 Compute 2PA using the fastest algorithm (use σ~-intermediates for canonical and σ-intermediates for RI/CD response calculations). 2 Use σ-intermediates for 2PA response equation calculations. 3 Use σ~-intermediates for 2PA response equation calculations.
RECOMMENDATION:
       Additional response equations (6 for each target state) will be solved, which increases the cost of calculations. The cost of 2PA moments is about 10 times that of energy calculation. Use the default algorithm. Setting CC_EOM_2PA >0 turns on CC_TRANS_PROP.

CC_EOM_2PA_XCONV

CC_EOM_2PA_XCONV
       Convergence criterion for the response vectors (norm of the difference) of the DIIS solver for damped response equations in 2PA and RIXS calculations.
TYPE:
       INTEGER
DEFAULT:
       5 Corresponding to 10-5
OPTIONS:
       n Corresponding to 10-n convergence criterion.
RECOMMENDATION:
       Use the default in double precision. May reduce in single precision.

DALTON_XCONV

DALTON_XCONV
       Convergence criterion for the residuals (square norm) of the Dalton solver for response equations.
TYPE:
       INTEGER
DEFAULT:
       6 Corresponding to 10-6
OPTIONS:
       n Corresponding to 10-n convergence criterion.
RECOMMENDATION:
       Use the default in double precision. May reduce to 5 in single precision.

DALTON_MAXITER

DALTON_MAXITER
       Maximum number of iteration allowed for the Dalton solver for response equations.
TYPE:
       INTEGER
DEFAULT:
       100
OPTIONS:
       n User-defined number of iterations.
RECOMMENDATION:
       Default is usually sufficient

DALTON_MAXSPACE

DALTON_MAXSPACE
       Specifies maximum number of vectors in the subspace for the Dalton solver for response equations.
TYPE:
       INTEGER
DEFAULT:
       200
OPTIONS:
       n Up to n vectors per root before the subspace is reset.
RECOMMENDATION:
       Larger values increase disk storage but accelerate and stabilize convergence.

DALTON_PRECOND_START

DALTON_PRECOND_START
       Specifies the iteration number in the Dalton procedure for response equations from which the preconditioner is applied to the residuals.
TYPE:
       INTEGER
DEFAULT:
       1
OPTIONS:
       n User-defined iteration number.
RECOMMENDATION:
       Use default.

CALC_SOC

CALC_SOC
       Whether or not the spin-orbit couplings between CC/EOM/ADC/CIS/TDDFT electronic states will be calculated. In the CC/EOM-CC suite, by default the couplings are calculated between the CCSD reference and the EOM-CCSD target states. In order to calculate couplings between EOM states, CC_STATE_TO_OPT must specify the initial EOM state. If NTO analysis is requested, analysis of spinless transition density matrices will be performed and the spin-orbit integrals over NTO pairs will be printed.
TYPE:
       INTEGER/LOGICAL
DEFAULT:
       FALSE (no spin-orbit couplings will be calculated)
OPTIONS:
       0/FALSE (no spin-orbit couplings will be calculated) 1/TRUE Activates SOC calculation. EOM-CC/EOM-MP2 only: spin-orbit couplings will be computed with the new code with L+/L- averaging 2 EOM-CC/EOM-MP2 only: spin-orbit couplings will be computed with the new code without L+/L- averaging 3 EOM-CC/EOM-MP2 only: spin-orbit couplings will be computed with the legacy code 4 One-electron spin-orbit couplings will be computed with effective nuclear charges (with L+/L- averaging for EOM-CC/MP2)
RECOMMENDATION:
       CCMAN2 supports several variants of SOC calculation for EOM-CC/EOM-MP2 methods. One-electron and mean-field two-electron SOCs will be computed by default. To enable full two-electron SOCs, two-particle EOM properties must be turned on (see CC_EOM_PROP_TE).

CALC_NAC

CALC_NAC
       Whether or not nonadiabatic couplings will be calculated for the EOM-CC, CIS, and TDDFT wave functions.
TYPE:
       INTEGER
DEFAULT:
       0 (do not compute NAC)
OPTIONS:
       1 NYI for EOM-CC 2 Compute NACs using Szalay’s approach (this what needs to be specified for EOM-CC).
RECOMMENDATION:
       Additional response equations will be solved and gradients for all EOM states and for summed states will be computed, which increases the cost of calculations. Request only when needed and do not ask for too many EOM states.

CC_POL

CC_POL
       Specifies the approach for calculating the polarizability of the CCSD wave function.
TYPE:
       INTEGER
DEFAULT:
       0 (CCSD polarizability will not be calculated)
OPTIONS:
       1 (analytic-derivative or response-theory mixed symmetric-asymmetric approach) 2 (analytic-derivative or response-theory asymmetric approach) 3 (expectation-value approach with right response intermediates) 4 (expectation-value approach with left response intermediates) 13 (damped-response expectation-value approach with right response intermediates) 14 (damped-response expectation-value approach with left response intermediates) 15 (damped-response expectation-value approach with first-order response density matrices)
RECOMMENDATION:
       CCSD polarizabilities are expensive since they require solving three/six (for static) or six/twelve (for dynamical) additional response equations. Do no request this property unless you need it.

EOM_POL

EOM_POL
       Specifies the approach for calculating the polarizability of the EOM-CCSD wave function.
TYPE:
       INTEGER
DEFAULT:
       0 (EOM-CCSD polarizability will not be calculated)
OPTIONS:
       1 (analytic-derivative or response-theory mixed symmetric-asymmetric approach) 2 (analytic-derivative or response-theory asymmetric approach) 3 (expectation-value approach with right response intermediates) 4 (expectation-value approach with left response intermediates)
RECOMMENDATION:
       EOM-CCSD polarizabilities are expensive since they require solving three/nine (for static) or six/eighteen (for dynamical) additional response equations. Do no request this property unless you need it.

CC_1HPOL

CC_1HPOL
       Specifies the approach for calculating the first hyperpolarizability of the CCSD wave function.
TYPE:
       INTEGER
DEFAULT:
       0 (CCSD first hyperpolarizability will not be calculated)
OPTIONS:
       1 (damped-response expectation-value approach with only first-order response wave functions) 3 (damped-response expectation-value approach with second-order response density matrices for wave-function and natural orbital analyses)
RECOMMENDATION:
       CCSD first hyperpolarizabilities are expensive since they require solving a huge number of first- and second-order response equations. Do no request this property unless you need it.

CC_EOM_PROP_TE

CC_EOM_PROP_TE
       Request for calculation of non-relaxed two-particle EOM-CC properties. The two-particle properties currently include S^2. The one-particle properties also will be calculated, since the additional cost of the one-particle properties calculation is inferior compared to the cost of S^2. The variable CC_EOM_PROP must be also set to TRUE. Alternatively, CC_CALC_SSQ can be used to request S^2 calculation.
TYPE:
       LOGICAL
DEFAULT:
       FALSE (no two-particle properties will be calculated)
OPTIONS:
       FALSE, TRUE
RECOMMENDATION:
       The two-particle properties are computationally expensive since they require calculation and use of the two-particle density matrix (the cost is approximately the same as the cost of an analytic gradient calculation). Do not request the two-particle properties unless you really need them.

CC_FULLRESPONSE

CC_FULLRESPONSE
       Fully relaxed properties (with or without orbital relaxation terms) will be computed. The variable CC_EOM_PROP must be also set to TRUE.
TYPE:
       INTEGER
DEFAULT:
       0 (no amplitude and orbital response will be calculated)
OPTIONS:
       1 (both amplitude and orbital response will be calculated) 2 (only amplitude response will be calculated)
RECOMMENDATION:
       Not available for non-UHF/RHF references. Only available for EOM/CI methods for which analytic gradients are available.

CC_SYMMETRY

CC_SYMMETRY
       Controls the use of symmetry in coupled-cluster calculations
TYPE:
       LOGICAL
DEFAULT:
       TRUE
OPTIONS:
       TRUE Use the point group symmetry of the molecule FALSE Do not use point group symmetry (all states will be of A symmetry).
RECOMMENDATION:
       It is automatically turned off for any finite difference calculations, e.g. second derivatives.

STATE_ANALYSIS

STATE_ANALYSIS
       Activates excited state analyses using libwfa.
TYPE:
       LOGICAL
DEFAULT:
       FALSE (no excited state analyses)
OPTIONS:
       TRUE, FALSE
RECOMMENDATION:
       Set to TRUE if excited state analysis is required, but also if plots of densities or orbitals are needed. For details see Section 10.2.9.

G_TENSOR

G_TENSOR
       Activates g-tensor calculation.
TYPE:
       LOGICAL
DEFAULT:
       FALSE
OPTIONS:
       FALSE (or 0) Don’t calculate g-tensor TRUE (or 1) Calculate g-tensor.
RECOMMENDATION:
       None.

Note:  g-Tensor calculations are only available for CCSD.

7.10.21.1 Examples

Example 7.85  Geometry optimization for the excited open-shell singlet state, B21, of methylene followed by the calculations of the fully relaxed one-electron properties using EOM-EE-CCSD.

$molecule
   0 1
   C
   H  1 rCH
   H  1 rCH 2 aHCH

   rCH    = 1.083
   aHCH   = 145.
$end

$rem
   JOBTYPE                   OPT
   METHOD                    EOM-CCSD
   BASIS                     cc-pVTZ
   SCF_GUESS                 CORE
   SCF_CONVERGENCE           9
   EE_SINGLETS               [0,0,0,1]
   EOM_NGUESS_SINGLES        2
   CC_STATE_TO_OPT           [4,1]
   EOM_DAVIDSON_CONVERGENCE  9    use tighter convergence for EOM amplitudes
$end

@@@

$molecule
   read
$end

$rem
   METHOD               EOM-CCSD
   BASIS                cc-pVTZ
   SCF_GUESS            READ
   EE_SINGLETS          [0,0,0,1]
   EOM_NGUESS_SINGLES   2
   CC_EOM_PROP          1  calculate properties for EOM states
   CC_FULLRESPONSE      1  use fully relaxed properties
$end

Example 7.86  Property and transition property calculation on the lowest singlet state of CH2 using EOM-SF-CCSD.

$molecule
   0 3
   C
   H  1 rch
   H  1 rch 2 ahch

   rch  = 1.1167
   ahch = 102.07
$end

$rem
   METHOD             eom-ccsd
   BASIS              cc-pvtz
   SCF_GUESS          core
   SCF_CONVERGENCE    9
   SF_STATES          [2,0,0,3]   Get three 1^B2 and two 1^A1 SF states
   CC_EOM_PROP        1
   CC_TRANS_PROP      1
   CC_STATE_TO_OPT    [4,1] First EOM state in the 4th irrep
$end

Example 7.87  Calculation of EOM transition strength using length, momentum, and mixed gauges.

$comment
EOM-CC oscillator strength using three gauges
$end

$molecule
0 1
C       1.2509987    -0.0000000     0.0000000
C      -1.2509987     0.0000000    -0.0000000
H       2.3262529     1.8903377     0.4190778
H       2.3262529    -1.8903377    -0.4190778
H      -2.3262529     1.8903377    -0.4190778
H      -2.3262529    -1.8903377     0.4190778
$end

$rem
    method = ccsd
    input_bohr = true
    ee_singlets [0,0,2,2]
    basis = 6-31g
    cc_trans_prop = true
    cc_ref_prop = 1
    cc_eom_prop = 1
$end

$trans_prop
  state_list
    ref
    ee_singlets 0 0
  end_list
  calc dipole linmom
$end

Example 7.88  Calculation of ECD using EOM-CCSD wavefunctions.

$comment
Calculation of ECD  using EOM-CC wave-functions
$end

$molecule
0 1
C       1.2509987    -0.0000000     0.0000000
C      -1.2509987     0.0000000    -0.0000000
H       2.3262529     1.8903377     0.4190778
H       2.3262529    -1.8903377    -0.4190778
H      -2.3262529     1.8903377    -0.4190778
H      -2.3262529    -1.8903377     0.4190778
$end

$rem
method = ccsd
input_bohr = true
ee_singlets [0,0,2,2]
basis = 6-31g
cc_trans_prop = true
cc_ref_prop = 1
cc_eom_prop = 1
cc_eom_ecd  = 1 ! keyword to activate ECD
$end

@@@
$comment
Calculation of ECD  using EOM-CC wave-functions
using trans_prop section
$end

$molecule
0 1
C       1.2509987    -0.0000000     0.0000000
C      -1.2509987     0.0000000    -0.0000000
H       2.3262529     1.8903377     0.4190778
H       2.3262529    -1.8903377    -0.4190778
H      -2.3262529     1.8903377    -0.4190778
H      -2.3262529    -1.8903377     0.4190778
$end

$rem
method = ccsd
input_bohr = true
ee_singlets [0,0,2,2]
basis = 6-31g
cc_trans_prop = true
cc_ref_prop = 1
cc_eom_prop = 1
$end

$trans_prop
state_list
    ref
    ee_singlets 0 0
    end_list
    calc ecd
$end

Example 7.7.89  Geometry optimization with tight convergence for the 2A1 excited state of CH2Cl, followed by calculation of non-relaxed and fully relaxed permanent dipole moment and S^2.

$molecule
   0 2
   H
   C   1  CH
   CL  2  CCL  1  CCLH
   H   2  CH   3  CCLH  1  DIH

   CH   = 1.096247
   CCL  = 2.158212
   CCLH = 122.0
   DIH  = 180.0
$end

$rem
   JOBTYPE                    OPT
   METHOD                     EOM-CCSD
   BASIS                      6-31G*  Basis Set
   SCF_GUESS                  SAD
   EOM_DAVIDSON_CONVERGENCE   9    EOM amplitude convergence
   CC_T_CONV                  9    CCSD amplitudes convergence
   EE_STATES                  [0,0,0,1]
   CC_STATE_TO_OPT            [4,1]
   EOM_NGUESS_SINGLES         2
   GEOM_OPT_TOL_GRADIENT      2
   GEOM_OPT_TOL_DISPLACEMENT  2
   GEOM_OPT_TOL_ENERGY        2
$end

@@@

$molecule
   read
$end

$rem
   METHOD             EOM-CCSD
   BASIS              6-31G*  Basis Set
   SCF_GUESS          READ
   EE_STATES          [0,0,0,1]
   EOM_NGUESS_SINGLES  2
   CC_EOM_PROP        1   calculate one-electron properties
   CC_EOM_PROP_TE     1   and two-electron properties (S^2)
$end

@@@

$molecule
   read
$end

$rem
   METHOD              EOM-CCSD
   BASIS               6-31G*  Basis Set
   SCF_GUESS           READ
   EE_STATES           [0,0,0,1]
   EOM_NGUESS_SINGLES  2
   CC_EOM_PROP         1  calculate one-electron properties
   CC_EOM_PROP_TE      1  and two-electron properties (S^2)CC_EXSTATES_PROP 1
   CC_FULLRESPONSE     1  same as above, but do fully relaxed properties
$end

Example 7.90  CCSD calculation on three A2 and one B2 state of formaldehyde. Transition properties will be calculated between the third A2 state and all other EOM states.

$molecule
   0  1
   O
   C  1  1.4
   H  2  1.0  1  120
   H  2  1.0  1  120  3 180
$end

$rem
   BASIS             6-31+G
   METHOD            EOM-CCSD
   EE_STATES         [0,3,0,1]
   CC_STATE_TO_OPT   [2,3]
   CC_TRANS_PROP     true
$end

Example 7.91  EOM-IP-CCSD geometry optimization of X B22 state of H2O+.

$molecule
   0 1
   H    0.774767     0.000000     0.458565
   O    0.000000     0.000000    -0.114641
   H   -0.774767     0.000000     0.458565
$end

$rem
   JOBTYPE           opt
   METHOD            eom-ccsd
   BASIS             6-311G
   IP_STATES         [0,0,0,1]
   CC_STATE_TO_OPT   [4,1]
$end

Example 7.7.92  CAP-EOM-EA-CCSD geometry optimization of the B12 anionic resonance state of formaldehyde. The applied basis is aug-cc-pVDZ augmented by 3s3p diffuse functions on heavy atoms.

$molecule
   0 1
   C       0.0000000000     0.0000000000     0.5721328608
   O       0.0000000000     0.0000000000    -0.7102635035
   H       0.9478180646     0.0000000000     1.1819748108
   H      -0.9478180646     0.0000000000     1.1819748108
$end

$rem
   JOBTYPE                    opt
   METHOD                     eom-ccsd
   BASIS                      gen
   N_FROZEN_CORE              0
   SCF_CONVERGENCE            9
   CC_CONVERGENCE             9
   EOM_DAVIDSON_CONVERGENCE   9
   EA_STATES                  [0,0,0,2]
   CC_STATE_TO_OPT            [4,1]
   XC_GRID                    000250000974
   COMPLEX_CCMAN              1
$end

$complex_ccman
   CS_HF 1
   CAP_TYPE 1
   CAP_ETA 60
   CAP_X 3850
   CAP_Y 2950
   CAP_Z 6100
$end

$basis
 H   0
 S   3  1.00
       13.0100000         0.196850000E-01
       1.96200000         0.137977000
      0.444600000         0.478148000
 S   1  1.00
      0.122000000          1.00000000
 P   1  1.00
      0.727000000          1.00000000
 S   1  1.00
      0.297400000E-01      1.00000000
 P   1  1.00
      0.141000000          1.00000000
 ****
 C   0
 S   8  1.00
       6665.00000         0.692000000E-03
       1000.00000         0.532900000E-02
       228.000000         0.270770000E-01
       64.7100000         0.101718000
       21.0600000         0.274740000
       7.49500000         0.448564000
       2.79700000         0.285074000
      0.521500000         0.152040000E-01
 S   8  1.00
       6665.00000        -0.146000000E-03
       1000.00000        -0.115400000E-02
       228.000000        -0.572500000E-02
       64.7100000        -0.233120000E-01
       21.0600000        -0.639550000E-01
       7.49500000        -0.149981000
       2.79700000        -0.127262000
      0.521500000         0.544529000
 S   1  1.00
      0.159600000          1.00000000
 P   3  1.00
       9.43900000         0.381090000E-01
       2.00200000         0.209480000
      0.545600000         0.508557000
 P   1  1.00
      0.151700000          1.00000000
 D   1  1.00
      0.550000000          1.00000000
 S   1  1.00
      0.469000000E-01     1.00000000
 P   1  1.00
      0.404100000E-01     1.00000000
 D   1  1.00
      0.151000000         1.00000000
 S   1  1.00
      0.234500000E-01      1.00000000
 S   1  1.00
      0.117250000E-01      1.00000000
 S   1  1.00
      0.058625000E-01      1.00000000
 P   1  1.00
      0.202050000E-01      1.00000000
 P   1  1.00
      0.101025000E-01      1.00000000
 P   1  1.00
      0.050512500E-01      1.00000000
 ****
 O   0
 S   8  1.00
       11720.0000         0.710000000E-03
       1759.00000         0.547000000E-02
       400.800000         0.278370000E-01
       113.700000         0.104800000
       37.0300000         0.283062000
       13.2700000         0.448719000
       5.02500000         0.270952000
       1.01300000         0.154580000E-01
 S   8  1.00
       11720.0000        -0.160000000E-03
       1759.00000        -0.126300000E-02
       400.800000        -0.626700000E-02
       113.700000        -0.257160000E-01
       37.0300000        -0.709240000E-01
       13.2700000        -0.165411000
       5.02500000        -0.116955000
       1.01300000         0.557368000
 S   1  1.00
      0.302300000          1.00000000
 P   3  1.00
       17.7000000         0.430180000E-01
       3.85400000         0.228913000
       1.04600000         0.508728000
 P   1  1.00
      0.275300000          1.00000000
 D   1  1.00
       1.18500000          1.00000000
 S   1  1.00
      0.789600000E-01      1.00000000
 P   1  1.00
      0.685600000E-01      1.00000000
 D   1  1.00
      0.332000000          1.00000000
 S   1  1.00
      0.394800000E-01      1.00000000
 S   1  1.00
      0.197400000E-01      1.00000000
 S   1  1.00
      0.098700000E-01      1.00000000
 P   1  1.00
      0.342800000E-01      1.00000000
 P   1  1.00
      0.171400000E-01      1.00000000
 P   1  1.00
      0.085700000E-01      1.00000000
 ****
$end

Example 7.93  Calculating resonant 2PA with degenerate photons.

$molecule
   0 1
   O
   H  1 0.959
   H  1 0.959 2 104.654
$end

$rem
   METHOD         eom-ccsd
   BASIS          aug-cc-pvtz
   EE_SINGLETS    [1,0,0,0]   1A_1 state
   CC_TRANS_PROP  1    Compute transition properties
   CC_EOM_2PA     1    Calculate 2PA cross-sections using the fastest algorithm
$end

Example 7.94  Non-degenerate, resonant 2PA scan over a range of frequency pairs.

$molecule
   0 1
   O
   H  1 0.959
   H  1 0.959 2 104.654
$end

$rem
   METHOD         eom-ccsd
   BASIS          aug-cc-pvdz
   EE_SINGLETS    [2,0,0,0]  Two A_1 states
   CC_TRANS_PROP  1          Calculate transition properties
   CC_EOM_2PA     1          Calculate 2PA cross-sections using the fastest algorithm
$end

$2pa
   n_2pa_points 11
   omega_1 500000 5000
$end

Example 7.95  Resonant 2PA with degenerate photons between two excited states.

$molecule
   0 1
   O
   H  1 0.959
   H  1 0.959 2 104.654
$end

$rem
   METHOD          eom-ccsd
   BASIS           aug-cc-pvtz
   EE_SINGLETS     [2,0,0,0] Two A_1 states
   CC_STATE_TO_OPT [1,1]     "Reference" state for transition properties is 1A_1 state
   CC_TRANS_PROP   1         Compute transition properties
   CC_EOM_2PA      1         Calculate 2PA cross-sections using the fastest algorithm
$end

Example 7.96  Calculation of 1st hyperpolarizability for CCSD wave function for LiH using the framework of damped response theory and the expectation-value approach for a range of frequencies.

$comment
Calculation of static and dynamical first hyperpolarizability for CCSD wave function
for LiH with STO-3G basis set using the framework of damped response theory and
the expectation-value approach.
The property for the following set of photons is calculated:
(omega_1, omega_2; omega_3) in cm-1
(0, 0; 0), (2500, 0; -2500), (5000, 0; -5000), (0, 3500; -3500),
(0, 7000; -7000), (2500, 3500; -6000), (2500, 7000; -9500),
(5000, 3500; -8500), (5000, 7000; -12000)
$end

$molecule
0 1
H
Li 1 1.6
$end

$rem
METHOD           ccsd
BASIS            sto-3g
CC_REF_PROP      1         ! required for CCSD property calculation
CC_1HPOL         1         ! computes first hyperpolarizability using first-order response wave functions only
MEM_STATIC       400
CC_MEMORY        2000
THRESH           13
SCF_CONVERGENCE  10
CC_CONVERGENCE   9
$end

$1hpol
omega_1 0 2500000 3 0.01  ! scans the first photon frequency from 0 cm-1 to 5000 cm-1 in 3-1=2 steps of 2500, corresponding damping is 0.01 hartrees
omega_2 0 3500000 3 0.01  ! scans the second photon frequency from 0 cm-1 to 7000 cm-1 in 3-1=2 steps of 3500, corresponding damping is 0.01 hartrees
omega_3 0.01              ! damping for the third photon is 0.01 hartrees
$end

Example 7.97  Mean-field spin-orbit calculation between two excited triplets in acetylene-O intermediate.

$molecule
   0 1
   C        -0.0303943366   -0.3149506151   -0.0436827067
   H        -0.1031279784   -1.4353675705   -0.1647400816
   O         1.0178175761    0.2350702146    0.2517598501
   C        -1.3252768442    0.1905302054   -0.4205132671
   H        -2.0767072171    0.1461814657    0.3842573052
$end

$rem
   BASIS             cc-pvdz
   METHOD            eom-ccsd
   SYM_IGNORE        true
   SF_STATES         [2]
   CC_STATE_TO_OPT   [1,1]
   THRESH            14
   CALC_SOC          1
   CC_TRANS_PROP     1
$end

Example 7.98  Mean-field spin-orbit calculation between the reference singlet and excited triplet states for acetylene-O intermediate.

$molecule
0 1
  C        -0.0303943366   -0.3149506151   -0.0436827067
  H        -0.1031279784   -1.4353675705   -0.1647400816
  O         1.0178175761    0.2350702146    0.2517598501
  C        -1.3252768442    0.1905302054   -0.4205132671
  H        -2.0767072171    0.1461814657    0.3842573052
$end

$rem
   BASIS           cc-pvdz
   METHOD          eom-ccsd
   SYM_IGNORE      true
   EE_TRIPLETS     [1]
   THRESH          14
   CALC_SOC        1
   CC_TRANS_PROP   1
$end

Example 7.99  Computation of spin-orbit couplings between closed-shell singlet and MS=1 triplet state in NH using EOM-SF-CCSD.

$molecule
   0 3
   N
   H N 1.0450
$end

$rem
   METHOD          = eom-ccsd
   BASIS           = 6-31g
   SF_STATES       = [1,2,0,0]
   CC_TRANS_PROP   = true
   CALC_SOC        = 3         ! legacy code
   CC_STATE_TO_OPT = [1,1]
$end

Example 7.100  Computation of spin-orbit couplings in neutral hextet (tpa)Fe complex (stripped ligands) by EOM-EA-MP2 method using pseudopotentials and effective nuclear charges.

$comment
Spin-orbit coupling calculation with SBKJC ecp using default effective nuclear
charges.  Computes SOC in neutral hextet (tpa)Fe geometry (stripped ligands)
by EOM-EA-MP2 method and high-spin reference.
$end

$molecule
0 6
  N   -0.0330663   -0.2576466    1.3744726
  N    2.0052862   -0.4826730   -0.5758819
  N   -1.9801232   -0.6573608   -0.6407513
  N   -0.0634263    1.4157074   -0.9056826
 Fe    0.0133915   -0.5560750   -0.6002859
  H   -0.0630940   -1.1802863    1.8620650
  H   -0.8780689    0.2958440    1.6401738
  H    2.3459249   -0.6439674   -1.5498484
  H    2.3506743   -1.2708551    0.0162081
  H   -2.2816187   -0.8324531   -1.6252623
  H   -2.3957415    0.2480261   -0.3283621
  H    0.0565056    1.5985967   -1.9267087
  H    0.7257691    1.8766147   -0.3993792
  H    0.8165651    0.2643868    1.6852415
$end

$rem
   METHOD                = EOM-MP2
   EOM_EA_BETA           = [5]
   MAX_SCF_CYCLES        = 300
   SCF_ALGORITHM         = gdm
   SCF_GUESS             = autosad
   EOM_PRECONV_SINGLES   = 1
   CALC_SOC              = 4
   CC_TRANS_PROP         = 2
   BASIS  =   SBKJC           [  use effective charges of ecps in soc calculation]
   ECP = fit-SBKJC
$end

Example 7.101  Computation of spin-orbit coupling in ClO using all-electron basis set, user-provided effective nuclear charges, and EOM-IP wave-functions.

$comment
Spin-orbit coupling calculation using all-electron basis set
and user-provided effective nuclear charges by
using EOM-IP wave-functions.
$end

$molecule
-1 1
  Cl   -0.9937913   -0.6696391   -1.9087016
  O    0.3415336   -0.1593825   -1.2619353
$end

$rem
jobtype             = sp
method              = eom-ccsd
basis               = 6-31G
print_general_basis = 1
scf_convergence     = 12
cc_convergence      = 10
eom_davidson_conv   = 8
eom_ip_alpha        = [0,0,1,1]
cc_eom_prop         = 1
cc_ref_prop         = 1
cc_trans_prop       = 1
cc_state_to_opt     = [3,1]
calc_soc            = 4
$end

$soc_eff_charges
8.0 6.0
17.0 11.0
$end

Example 7.102  Computation of nonadiabatic couplings between EOM-EE states within triplet (first job) and singlet (second job) manifolds.

$molecule
   +1 1
   H          0.00000        0.00000        0.0
   He         0.00000        0.00000        3.0
$end

$rem
   JOBTYPE                  = FORCE
   METHOD                   = EOM-CCSD
   BASIS                    = cc-pVDZ
   INPUT_BOHR               = true
   EE_TRIPLETS              = [2]
   CC_EOM_PROP              = true
   SYM_IGNORE               = true  Do not reorient molecule and turn off symmetry
   CALC_NAC                 = 2     Invoke Szalay NAC
   EOM_DAVIDSON_CONVERGENCE = 9     tight davidson convergence
   SCF_CONVERGENCE          = 9     Hartree-Fock convergence threshold 1e-9
   CC_CONVERGENCE           = 9
$end

@@@

$molecule
   read
$end

$rem
   JOBTYPE                  = FORCE
   METHOD                   = EOM-CCSD
   BASIS                    = cc-pVDZ
   INPUT_BOHR               = true
   EE_STATES                = [2]   singlets
   SYM_IGNORE               = true  Do not reorient molecule and turn off symmetry
   CALC_NAC                 = 2     Invoke Szalay NAC
   EOM_DAVIDSON_CONVERGENCE = 9     tight davidson convergence
   SCF_CONVERGENCE          = 9     Hartree-Fock convergence threshold 1e-9
   CC_CONVERGENCE           = 9
$end

Example 7.103  Calculation of the static dipole polarizability of the CCSD wave function of Helium.

$molecule
   0 1
   He
$end

$rem
   METHOD            ccsd
   BASIS             cc-pvdz
   CC_REF_PROP       1
   CC_POL            2
   CC_DIIS_SIZE      15
   CC_FULLRESPONSE   1
$end